This is probably a lie. The Google interview is not particularly hard. It might be hard if you absolutely refuse to ever let your eyes look at anything that could possibly be considered an "algorithms book", but otherwise... it's stuff that you will know if you care about computer programming at all. The questions are about applying big concepts, not implementation details of particular algorithms. (I couldn't write A* from memory, but I do know what an "admissible heuristic" is. And that's good enough to be hired by Google.)